<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>基础选择器</title>
    <style>
    #div1 {
        color:red;
    }

    div {
        color: green;
    }

    .cls1 {
        color: blue;
    }
    </style>
</head>
<body>

<div id="div1">旅游网</div>
<div>旅游网</div>

<p class="cls1">旅游网</p>

</body>
</html>